Compressor valve assembly and method of producing the same

ABSTRACT

A laminated valve plate assembly for a reciprocable piston compressor said plate being of the type formed substantially by stamping processes and characterized by being only two laminations thick and having at least some of the port-defining surfaces which are smooth and have compound curvatures that are inclined with respect to the plane of the plate to provide a less turbulent flow through the ports and to reduce the required thickness of the finished valve plate. The outlet end portions of both the intake and exhaust means comprise continuous slots formed by stamping processes and stamped parts while the inlet end portions of these port means comprise a plurality of discontinuous slots. Peripheral recesses are formed around the top and bottom surfaces of the plate by shearingly depressing the edges thereof to eliminate burrs and to protect the edges of the lapped top and bottom surfaces from damage due to rough handling prior to the installation of the valve assembly between the cylinder head and cylinder block of the compressor. The disclosure also includes novel methods for forming the abovementioned structures.

[ 5 Feb. 22, 1972 Hudson, Jr.

COMPRESSOR VALVE ASSEMBLYVANII) METHOD OF PRODUCING THE SAME Sharon J, Hudson, Jr., Lambertville,

Mich.

Sharon Manufacturing Company, Toledo, Ohio Filed: Nov. 25, 1969 Appl. No.: 879,863

Inventor:

Assignee:

References Cited UNITED STATES PATENTS 5/ 1939 Nickelsen ..137/493.8 5/1939 Engelman ....137/5l2.15 X 12/1955 Cooper ..l37/5l6.l5 5/1960 Gerteis ..l37/512.15 X

FOREIGN PATENTS OR APPLICATIONS 458,67910/1949 Italy ..l37/5l2 Primary Examiner-Robert G. Nilson Attorney-Harold F. Mensing [5 7] ABSTRACT A laminated valve plate assembly for a reciprocable piston by stamping processes and characterized by being only two laminations thick and having at least some of the port-defining surfaces which are smooth and have compound curvatures that are inclined with respect to the plane of the plate to provide a less turbulent flow through the ports and to reduce the required thickness of the finished valve plate. The outlet end portions of both the intake and exhaust means comprise continuous slots formed by stamping processes and stamped parts while the inlet end portions of these port means comprise a plurality of discontinuous slots. Peripheral recesses are formed around the top and bottom surfaces of the plate by shearingly depressing the edges thereof to eliminate burrs and to protect the edges of the lapped top and bottom surfaces from damage due to rough handling prior to the installation of the valve assembly between the cylinder head and cylinder block of the compressor. The disclosure also includes novel methods for forming the above-mentioned structures.

15 Claims, 6 Drawing Figures PAIENIEUFEB22 m2 SHEET 1 0F 2 V m a 4 56mm J Human/e.

COMPRESSOR VALVE ASSEMBLY AND METHOD OF PRODUCING THE SAME BACKGROUND OF INVENTION This invention relates to reciprocable piston compressors of 5 semblies at least one of these features and sometimes more of them were sacrificed for one reason or another including a lack of knowledge of how to economically manufacture a valve assembly incorporating all of these features. In some of the. prior art valve plates of the laminated type, three or more laminations were required to produce sufficient lateral offset between the intake and outlet ends of the intake ports. The ports in each laminations were perpendicular to the plane of I the lamination and were laterally offset slightly from the ports in the adjacent laminations to produce a laterally stepped aperture or port. These steps or ofi'sets cause undesired turbulence and impeded fluid flow therethrough.

Generally speaking the valve assembly of this invention basically has a laminated valve plate only two laminations in thickness. A series of intake ports and a series of exhaust ports are formed within these laminations primarily by stamping processes. Each series is arranged in a circle and the circles are concentric. All or a substantial portion of the intake portdefining surfaces of the laminar members are smoothly coined surfaces as opposed to the relatively rough port-defining sur-. faces formed in prior art plates by the shearing action of a piercing die or punch. The advantage of having a smooth portdefining surface is twofold. It reduces the resistance to fluid flow'through the ports. Also it prevents the formation of beads of brazing material on the port-defining surfaces which occurs frequently on the'roughly surfaced ports of prior art valve plates during the brazing process when the laminations are bonded together. The intake port-defining surfaces are curved in the direction of fluid flow to provide an improved flow pattern. All or a substantial portion of the intake port-defining surfaces are sharply inclined with respect to the plane of the plate to provide the desired lateral offset between the intake and outlet ends of the port in a minimum plate thickness.

The inlet end portions'of both the intake and the-exhaust ports comprise discontinuous annular slots disposed in the planes of their respective laminar members while the outlet end portions of these ports are uninterrupted or continuous annular slots similarly disposed in opposite laminar members. These continuous annular slots in the surfaces of the laminar members promote the most effective sealing of the ports when cooperating leaf valve members of the type common to such compressors are used. In prior art valve assemblies the continuous annular slots were machined in the surfaces of the laminar members by rotary cutters. The outlet end portion of the exhaust port means is formed in its respective laminar member by an annular die which penetrates only a portion of the thickness of the member. A segmented annular die, which is slightly narrower than the first die, pierces the remaining thickness of the laminar member and forms a series of arcuate slots spaced apart by radially extending webs. The uninterrupted annular slot at the outlet end of the intake port means is formed in its respective member by the edge of a large circular opening therein and the upright peripheral flange of a stamped disk member mounted concentrically in the circular opening. The outside diameter of the rim portion of the disk is smaller than the inside diameter of the circular opening and the edge of the rim is flush with the outer surface of the laminar member. lnwardly from the rim of the disk is a concentrically located series of slots corresponding to those of the exhaust ports in the opposite laminar member. Means are provided for readily bringing the exhaust ports in the disk and the exhaust ports in the laminar member into registry with each other. The port-defining members including the two laminar members and the stamped disk are preassembled and held together by rivet means and subsequently penna'nently bonded by brazing in a furnace. The planar surfaces of the plate are made parallel and smooth by machining, grinding and lapping after which the leaf valve members may be installed over the outlet ends of the ports to complete the valve assembly. A peripheral flange extending laterally outward from the sides of the valve plate is provided to protect the edges of the lapped surfaces from becoming damaged by improper handling.

Accordingly it is a general object of this invention to produce a compressor valve assembly having an improved design that is formed primarily by stamping processes. I

It is another object of this invention to produce such a valve assembly in which at least some of the port defining surfaces are smoothly contoured to provide a more efficient fluid flow therethrough.

It is still another object of this invention to produce an improved valve assembly which is efficient, durable, compact and economical to manufacture.

The above mentioned objects and other objects and advantages and the manner of attaining them will be apparent from the following description of a preferred embodiment of this invention made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view on a reduced scale of the components for a valve assembly made in accordance with this in vention showing the components displaced from their assembled positions to illustrate among other things the details of the abutting surfaces of the laminar members of the valve plate.

FIG. 2 is an enlarged sectional side view of a center portion of the assembled valve assembly taken along line 22 of FIG. 1 with parts broken away showing the cross-sectional configuration of the exhaust ports and the protective peripheral rim.

FIG. 3 is a further enlarged sectional side view similar to FIG. 2 but taken along line 3-3 showing the cross-sectional configuration of the intake port.

FIG. 4 is a still further enlarged sectional side view of an exhaust port portion of the top laminar member of the valve plate after the first step in the formation of this port has been completed.

FIG. 5 is a view similar to FIG. 4 taken after the second step in the formation of the port has been completed.

FIG. 6 is an enlarged perspective view of the stamped ported disk having tab means for registering the ports therein with the corresponding ports in the abutting plate member.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawings, particularly to FIG. I of the drawings, the components of the valve assembly 10 are arranged with respect to their assembled positions but are displaced therefrom aiong a central axis. The basic components of the valve assembly are the top or first laminar member 12, the bottom or second laminar member 14 a port defining central disk 16 and leaf valve members 18 and 20 respectively for closing the intake and exhaust port means in the laminar members. The laminar members 12 and 14 in combination with the circular disk 16 form the valve plate portion of the valve assembly 10. Two series of ports each arranged preferably in a circular pattemand concentrically disposed with respect to each other are formed in a central portion of the valve plate by these three components 12, I4 and 16. The outer series of ports is denoted as the intake port means 22. The total open area of the intake port means is substantially larger than the tuna; mm

total area of the inner series of ports which is denoted as the exhaust port means 24. The ratio between the areas of the two series generally corresponds to the compression ratio of the compressor. The laminar members 12 and 14 are preferably flat steel blanks made by stamping processes. The blanks shown in the drawings are substantially square but rectangular or circular blanks or blanks of any other desired outline may be used.

The portion of the exhaust port means extending through the top laminar member 12 may be formed in two operations. First a continuous annular slot 26 may be formed at the outlet end of the port means by striking the top or outer surface of laminar member 12 with an annular die while supporting the under surface of the laminar member with a die member having a concentrically disposed interrupted or segmented annular cavity of slightly smaller radial width. The stamping means is adjusted so that the annular die penetrates only a portion of the thickness of the laminar member, see FIG. 4. As a result metal is displaced from the surface of the laminar member and more or less extruded into the spaced apart sections of the segmented annular cavity of the supporting die member. The remaining portion 28 of the exhaust port means is produced by a piercing die or punch having a segmented annulus. The radial width of each of the annular sections of the piercing die is between the width of the continuous slot and the width of the metal portion extruded into the supporting die cavity, see FIGS. 4 and 5. With this method the piercing die is required to shear only a partial thickness of the laminar member. The portion of the intake ports produced by the segmented annular die comprises a plurality of arcuate slots separated from each other by radially extending web members 29.

The portion of the intake port means extending through the first laminar member may also be formed in two operations. First a piercing die or punch is used to produce a plurality of elongated slots having sides which are normal to the surfaces of the laminar member. Preferably these slots are arcuate with respect to the plane of the laminar members and are arranged annularly. The length of each slot, as defined by the number of degrees of are included between its ends, is preferably between about 35 and 90. Slots shorter than this range increase the resistance to fluid flow therethrough and if longer slots are used there is insufficient structural stability or support. To enhance fluid flow through the intake ports the sides of the slots nearest the center of the annulus are contoured and made smooth by means of a coining operation. Normally a finish having a roughness in the vicinity of about 50-150 microinches may be produced on the coined surfaces as opposed to a surface finish of about 250-500 microinches average on a sheared surface. The coined surface 30 may be straight or arcuate in the direction of fluid flow and have a slope of substantially less than 90 with respect to the plane of the plate as is best shown in FIG. 3. Preferably the coined surface is concave in the direction of fluid flow and has an average slope of less than 45. The sides of the web members 32 between the intake ports may converge in a direction towards the center of the laminar member 12. One or more of the process steps may be combined. In the alternative, the port-defining surfaces may be. formed in about the same manner as the exhaust ports were formed in the top laminar member. That is by first using a contoured coining die to form a first portion of the port defining surfaces and then using a piercing die to produce the remaining portion.

Laminar member 14 contains the outlet end of the intake port means 22 and the inlet end of the exhaust port means 24. One side of the continuous annular slot which forms the outlet end of the intake port means is defined by the surface of the large circular opening in laminar member 14. This port defining surface 34 is contoured by a coining operation to conform with the contoured surface 30 of the top laminar member 12, see FIG. 3. The other side of the annular slot is formed by the peripheral surface of disk 16.

Circular disk 16 has a peripheral flange 36 extending normally outward from its outer planar face and terminating flush with the adjacent surface of the surrounding laminar member 14. Ports of the same lateral size and shape as the exhaust ports extending through the abutting surface of laminar member 12 are provided through the plane of the disk. Locating means such as pairs 38 of small tabs which embrace the web members 29 of laminar member 14 may be provided to insure registry between the ports of the two members 14 and 16. The flange, tabs and ports may all be formed by stamping processes.

In order to assemble the components l2, l4 and 16 for brazing or bonding the abutting surfaces thereof together, apertures may be punched through the geometric centers of the port portions of laminar member 12 and disk 16 and also through outlying portions of laminar members 12 and 14. After appropriate fluxing and brazing compounds have been applied to the abutting surfaces of the members l2, l4 and 16 headless pins or rivets may be inserted in the apertures and staked or otherwise expanded to firmly hold the members in position while being transported through a brazing furnace.

After brazing, the outer surfaces of the valve plate may be machined or ground to the desired degree of flatness and parallelism and then lapped to produce the desired finish. Prior to the final machining or grinding operation the top and bottom peripheral edges may be shearingly displaced towards the center of the plate a portion of the thickness of the laminar members. The tip of the shearing die member may be angled slightly so as to urge the displaced metal laterally outward thereby forming a laterally extending peripheral rim 40 to protect the edges of the plate surface from damage which may prevent effective sealing between the valve plate and the compressor head or block.

Valve members 18 and 20 maybe installed over the outlet ends of the intake and exhaust port means 22 and 24 respectively by drilling and tapping the center pin 42 and attaching the valve members by means of fasteners, such as screws or rivets. The valve members are of the leaf type commonly used for compressors. They differ from each other primarily in size and the shape of the spring spokes. Both of the valve members have an annular port sealing portion of adequate size to seal their respective annular port outlets. lntegrally attached to the annular portion of each valve member and extending to its apertured center is'a pair of arcuate spring elements.

While the invention has been illustrated and described with respect to preferred structures and processes, it is to be understood that various modifications of the above will be apparent to those skilled in the art without departing from the scope of the invention which is defined by the appended claims.

What is claimed is:

1. A laminated valve plate for a reciprocating piston-type compressor comprising; first and second generally planar laminar members superimposed one upon the other with adjoining surfaces thereof sealingly bonded together, said first laminar member having intake and exhaust port means extending from its outer surface to its bonded surface with at least some of the port-defining portions of said first laminar member being disposed at an angle of less than 45 with respect to the plane of said bonded surface, port means through said second laminar member in fluid communication with said intake and exhaust port means of said first laminar member, and valve means disposed on the outside of each of said laminar members for alternately stopping the flow of fluid through said intake and exhaust port means.

2. A laminatedvalve plate according to claim 1 wherein at least some of the port defining surface of said second laminar member is disposed at an angle of less than with respect to the plane of said second laminar member.

3. A laminated valve plate according to claim 1 further comprising a stamped sheet metal disk disposed within said port means of said second laminar member and sealingly attached to said first laminar member, said disk having a peripheral rim extending from said first laminar member to a plane level with the adjacent outer surface of said second laminar member, said rim thereby defining a portion of an intake port portion of said port means in said second laminar member, said disk having a recessed portion adjacent said rim and having intake port means extending through said recessed portion in communication with said intake port means of said first laminar member.

4. A laminated valve plate according to claim 1 wherein the outlet end of said exhaust port means is formed by a continuous annular slot in the outside face of said first laminar member, said continuous annular slot having a depth less than the thickness of said first laminar member, the remaining portion of said exhaust port means in said first laminar member having a discontinuous annular slot divided by radially extending webs, and the outlet end of said intake port means is formed by a continuous annular slot extending completely through said second laminar member.

5. A laminated valve plate according to claim 1 wherein said intake port means in said first laminar member includes a plurality of circularly aligned arcuate slots divided from each other by generally radially extending web members with the opposite ends of each slot diverging in a radially outward direction with respect to each other.

6. A laminated valve plate according to claim 1 wherein at least some of said port-defining portions have a compound curvature.

7. A laminated valve plate according to claim 6 wherein said port-defining portions having said compound curvature have a smoothly coined surface.

8. A laminated valve plate for a reciprocating piston-type compressor comprising: first and second generally planar laminar members superimposed one upon the other with adjoining surfaces thereof sealingly bonded together, said first laminar member having annularly disposed arcuate slots forming intake and exhaust port means extending from its outer surface to its bonded surface with at least some of the slotdefining portions of said first laminar member being inclined at an acute angle with respect to the plane of the outside surface of said first laminar member, at least some of said slots having said acutely disposed portions also having an annular extent between 35 and 90, port means through said second laminar member in fluid communication with said intake and exhaust port means of said first laminar member, and valve means disposed on the outside of each of said laminar members for alternately stopping the flow of fluid through said intake and exhaust port means.

9. A laminated valve plate for a reciprocating piston-type compressor comprising: first and second generally planar laminar members superimposed one upon the other with adjoining surfaces thereof sealingly bonded together, said first laminar member having intake and exhaust port means extending from its outer surface to its bonded surface, port means through said second laminar member in fluid communication with said intake and exhaust port means of said first iaminar member, at least some of the portdefining surface of said laminar members having a smoothly coined surface, and valve means on the outer surface of said laminar members for alternately stopping a flow of fluid through said intake and exhaust port means.

10. A laminated valve plate according to claim 9 wherein at least a portion of said coined surface has a compound curvature.

11. A laminated valve plate according to claim 9 further comprising a stamped sheet metal disk disposed within said port means of said second laminar member and sealingly attached to said first laminar member, said disk having a peripheral rim extending from said first laminar member to a plane level with the adjacent outer surface of said second laminar member, said rim thereby defining a portion of an intake port portion of said port means in said second laminar member, said disk having a recessed portion adjacent said rim and having intake port means extending through said recessed portion in communication with said intake port means of said first laminar member.

12. A laminated valve plate for a reciprocating piston-type compressor comprising: first and second generally planar laminar members superimposed one upon the other with adjoining surfaces thereof sealingly bonded together, said first laminar member having two concentrically disposed series of elongated arcuate slots, with the inside series of slots forming exhaust port means and with the outside series of slots forming intake port means, the inner concentric surface of the intake port defining portion of said first laminar member being inclined with respect the plane of said member, a large circular aperture in said second laminar member for communicating with said intake and exhaust port means of said first member, and a stamped sheet metal disk concentrically disposed in said circular aperture and sealingly attached to said first member, said disk having a flat central portion with port means communicating with said exhaust ports of said first laminar member and having a peripheral rim portion extending from said first laminar member to a plane level with the adjacent outside planar surface of said second laminar member for cooperating with said circular aperture in said second laminar member to define an intake port means extending through said second laminar member.

13. A laminated valve plate according to claim 12 wherein said inclined surface is a smoothly coined surface.

14. A laminated valve plate according to claim 13 wherein said inclined surface has a compound curvature.

15. A laminated valve plate according to claim 12 wherein said exhaust port means in said first laminar member comprises an uninterrupted annular slot in the surface of the first laminar member extending partially through said first laminar member with the remaining portion of said exhaust port means through said member being a discontinuous annular slot formed by a plurality of radially extending web members. 

1. A laminated valve plate for a reciprocating piston-type compressor comprising; first and second generally planar laminar members superimposed one upon the other with adjoining surfaces thereof sealingly bonded together, said first laminar member having intake and exhaust port means extending from its outer surface to its bonded surface with at least some of the portdefining portions of said first laminar member being disposed at an angle of less than 45* with respect to the plane of said bonded surface, port means through said second laminar member in fluid communication with said intake and exhaust port means of said first laminar member, and valve means disposed on the outside of each of said laminar members for alternately stopping the flow of fluid through said intake and exhaust port means.
 2. A laminated valve plate according to claim 1 wherein at least some of the port defining surface of said second laminar member is disposed at an angle of less than 90* with respect to the plane of said second laminar member.
 3. A laminated valve plate according to claim 1 further comprising a stamped sheet metal disk disposed within said port means of said second laminar member and sealingly attached to said first laminar member, said disk having a peripheral rim extending from said first laminar member to a plane level with the adjacent outer surface of said second laminar member, said rim thereby defining a portion of an intake port portion of said port means in said second laminar member, said disk having a recessed portion adjacent said rim and having intake port means extending through said recessed portion in communication with said intake port means of said first laminar member.
 4. A laminated valve plate according to claim 1 wherein the outlet end of said exhaust port means is formed by a continuous annular slot in the outside face of said first laminar member, said continuous annular slot having a depth less than the thickness of said first laminar member, the remaining portion of said exhaust port means in said first laminar member having a discontinuous annular slot divided by radially extending webs, and the outlet end of said intake port means is formed by a continuous annular slot extending completely through said second laminar member.
 5. A laminated valve plate according to claim 1 wherein said intake port means in said first laminar member includes a plurality of circularly aligned arcuate slots divided from each other by generally radially extending web members with the opposite ends of each slot diverging in a radially outward direction with respect to each other.
 6. A laminated valve plate according to claim 1 wherein at least some of said port-defining portions have a compound curvature.
 7. A laminated valve plate according to claim 6 wherein said port-defining portions having said compound curvature have a smoothly coined surface.
 8. A laminated valve plate for a reciprocating piston-type compressor comprising: first and second generally planar laminar members superimposed one upon the otHer with adjoining surfaces thereof sealingly bonded together, said first laminar member having annularly disposed arcuate slots forming intake and exhaust port means extending from its outer surface to its bonded surface with at least some of the slot-defining portions of said first laminar member being inclined at an acute angle with respect to the plane of the outside surface of said first laminar member, at least some of said slots having said acutely disposed portions also having an annular extent between 35* and 90*, port means through said second laminar member in fluid communication with said intake and exhaust port means of said first laminar member, and valve means disposed on the outside of each of said laminar members for alternately stopping the flow of fluid through said intake and exhaust port means.
 9. A laminated valve plate for a reciprocating piston-type compressor comprising: first and second generally planar laminar members superimposed one upon the other with adjoining surfaces thereof sealingly bonded together, said first laminar member having intake and exhaust port means extending from its outer surface to its bonded surface, port means through said second laminar member in fluid communication with said intake and exhaust port means of said first laminar member, at least some of the port-defining surface of said laminar members having a smoothly coined surface, and valve means on the outer surface of said laminar members for alternately stopping a flow of fluid through said intake and exhaust port means.
 10. A laminated valve plate according to claim 9 wherein at least a portion of said coined surface has a compound curvature.
 11. A laminated valve plate according to claim 9 further comprising a stamped sheet metal disk disposed within said port means of said second laminar member and sealingly attached to said first laminar member, said disk having a peripheral rim extending from said first laminar member to a plane level with the adjacent outer surface of said second laminar member, said rim thereby defining a portion of an intake port portion of said port means in said second laminar member, said disk having a recessed portion adjacent said rim and having intake port means extending through said recessed portion in communication with said intake port means of said first laminar member.
 12. A laminated valve plate for a reciprocating piston-type compressor comprising: first and second generally planar laminar members superimposed one upon the other with adjoining surfaces thereof sealingly bonded together, said first laminar member having two concentrically disposed series of elongated arcuate slots, with the inside series of slots forming exhaust port means and with the outside series of slots forming intake port means, the inner concentric surface of the intake port defining portion of said first laminar member being inclined with respect the plane of said member, a large circular aperture in said second laminar member for communicating with said intake and exhaust port means of said first member, and a stamped sheet metal disk concentrically disposed in said circular aperture and sealingly attached to said first member, said disk having a flat central portion with port means communicating with said exhaust ports of said first laminar member and having a peripheral rim portion extending from said first laminar member to a plane level with the adjacent outside planar surface of said second laminar member for cooperating with said circular aperture in said second laminar member to define an intake port means extending through said second laminar member.
 13. A laminated valve plate according to claim 12 wherein said inclined surface is a smoothly coined surface.
 14. A laminated valve plate according to claim 13 wherein said inclined surface has a compound curvature.
 15. A laminated valve plate according to claim 12 wherein said exhaust port means in said first laminar member comprises an uninterrupted annular slot iN the surface of the first laminar member extending partially through said first laminar member with the remaining portion of said exhaust port means through said member being a discontinuous annular slot formed by a plurality of radially extending web members. 